Apparatus for testing cans.



J. W. DIXON.

APPARATUS FOR TESTING CANS.

APPLICATION rmm MAY 25, 1911.

Patented Nov. 24, 1914.

UNITED STATES PATENT OFFICE;

JAMES W. DIXON, OF CHICAGO, ILLINOIS, ASSIGNOR T0 AMERICAN CAN COMPANY, OF.

NEW YORK, N. Y., A CORPORATION OF NEW JERSEY.

APPARATUS FOR rss'rrirc. CANS.

Specification of Letterslatent.

Patented Nov. 24, 1914.

Application filed May 25, 1911. Serial No. 629,286.

creasing the sensitiveness of apparatus for testing cans for leaks by means of compressed air, and the invention consists 1n partially-filling the can to be tested with a bulk or mass to diminish the amount of compressed air contained in the can so that the ratiowhich the amount of air escaping by any leak in the can bears to the Whole amount of compressed air contained in the can will be multiplied, and the difference between the air pressure in a leaky can and the air pressure in a sound can'will be made thus more manifest.

In the accompanying drawings which form a part of this specification, Figure 1 is a side elevation, partly in section, of a hand operated air can tester. Fig. 2 is a section on the line 22 of Fig. 1.

In the drawing, 11 represents a can of the open mouthed variety to be tested.

12 is the can holder or cradle for supporting the tested can, and'which' is provided with a base plate 13 against which the can bottom rests. This cradle is shown to be mounted to slide on the rod 14 and to be moved on said rod by the foot lever 15 toward and away from the sealing head 16 provided with the rubber sealing cushion 17. Attached to the sealing head is the mass or bulk member 18, a cylindrical mass of approximately the dimensions and form of the interior of the can, and which, when the .can is pushed against the sealing head nearly fills the interior of the can, leaving, however, on the sides and bottom a clearance space for containing the compressed air. The bulk 18 is preferably provided with an aperture 19 for the passage of the com-- pressed air to the interior of the can, and this aperture is connected to the compressed air pipe 20 leading to the three-Way valve 21. Within the bulk 18 is the automatic air valve 22 and valve stem 23 so contrived that when the can is compressed against the sealing head, the end of the valve'rod comes in contact with the bottom of the can and opens the valve to admit the compressed air to the interior of the can and when the can is withdrawn from the sealing. head, the pressure of the air automatically closes said valve against the further passage of compressed air. Connected to the threeway valve 21 is the pipe 24 communicating with the compressed air supply tank 25 and communicating with the same threeway valve is the pi )e 26 leading to one side of the diaphragm 2 contained in the chamber 28, the chamber on. the other side of the said diaphragm being connected by the ipe 29 with the compressed air tank 25. nected to the diaphragm and moving there with is'thc indicator 30. i

In operation, a can to be tested is placed in the machine upon the cradle 12 and its open mouth, by means of the foot lever, is

brought over the bulk 18 and in contact with the sealing head, thereby sealing the' interior of the can from outside air. By

this movement, the stem of the valve, striking against the bottom of the can, opens the valve and admits to the interior of the can compressed air from the tank 25 through the pipe 24, valve 21 and pipe-20. Thereupon, the valve 21. is rotated so that the pipe- 20 is put. into communication with the pipe 26, to thus bring the pressure of the air contained within the can to bear upon the upper side of the diaphragm, while at the 'same time the air from the tankbears upon the lower sideof the diaphragm, So long as no air leaks out of the can these pressures should, of course, balance, and no movement will be indicated on the indicator. But after the lapse of a suflicient time to permit the air to escape, if there be a leak in the can, this balance will be destroyed and the superior pressure of the tank will thereupon move the diaphragm and give an indication on the indicator disclosing the fact that the can leaks. i

The object of partially filling the interior of the can with the displacing bulk is to diminish the space for contaimn the compressed air, thus making the action of the tester more sensitive. The compressed air is very elastic and the leaks are apt to.be

very minute, andwhere a great bulk of air" is in question, a minute leak will not be so readily detected as where a small bulk of air is in question. Thus,'for example, if the chamber or can to be tested contains ten such case the lealg would empty the small- 5.

gallons ofia'ir it would take ten times as long for a lealt to empty it, as it would if the can contained but one gallon of air, and 1n amount of air while it would only-reduce the pressure in the can containing the large amount of air by one tenth. It will thus be seen that the introduction of'tho displacing bulk in the can by diminishing the room for compressed air, and the consequent volume thereof, increases the sensitivencssbf the testing apparatus and also diminishes the length of time required for the test.

1 claim': i 1. In a can tester of the character described a base havinga flat surface against the can'and said body,

which the open end of a can ois adapted'to be seated and sealed, an air-displacing body secured to saidbase and so positioned'that 7 when the can is seated on the base the body will be located entirely within the can but free from engagement therewith, and means; for admitting air to theinterior oi: the can so seated, the air entering the spacebetweensubstantially as de-" scribed. v f 2. In a can tester of the character 'de' scribed, a base having a surface against -i ng member cooperable with the base 'to' clamp the can 'the1'ebetween,'and means for" 40: air-displacing body substantially as speciwhich the open end of a can is adapted to 'bef I seated and sealed, an air-displacing body:

mounted on said base and so positioned that when the can is seated on the base the body will be located entirely within the can-but free from engagementtherewith, a clampadmittingair to the interior of the can when seated and sealed on the'base, the air occupying the space between the can andsaid fled.

3. In a can tester of the character described, a base havinga flat surface against which the open end oi a can is adapted to be seated and sealed an air-displacing body secured to said base and so positioned that when the can is seated on tile base the body will be located entirely'within the can but free from engagement therewith, means for scribed, means on'which the open end of a can 15 adapted to be seated and-sealed, an a aii displacing body associated with said means andso positioned that when the can is,

seated and s ealed,the body will be located entirelyv within the can but free from engage me'nt therewith, means for admitting air to the interior of the can when so seated and scaled, theair entering the space between the can and said body, and means for indicating a change in the air pressure inthe sealed can after avsupply of air. thereto has been shut ofi, substantially as specified 5.. lna'eanetester, in combination: a seal-.

mg 'baseand a movable 'irnember adapted to clamp a can againstthe. :base and seal the cany a compressed. air supply, connections i'rom the; supply adapted to monduct the compressed" airto the interiori of the sealed can and hatinga; v'alve included therein which is normally closed butis adapted to be opened when the can is in sealed position, an air chamber 1 having movable dia-- phralgm thereim'; conneetions" from the air supply to ithech'amb'erjon oneside ofthe diaphragrmand connections fromthe chamber onsthe other side; of the diaphragm-and eom municating with the/connections from the supply to the interior of the sealed can, an indicatingdial and finger a connecting member between the finger and the diaphragm; and ruean's for shutting ofi the supply of i com i the interior ofthe can and; forming a path for the compressed ait iirom pressed to the can to oneside of the: diaphragm in the chamben /Vitnesses PEARL Annexes, nElTZ-1Eli .AERAMS,

jJAMES /V'. erase 

